1. Field
The present disclosure relates to vehicular radar systems and, in particular, to a grid structure for supporting an array of end-fire antennas without significant interference with signals transmitted by the array of end-fire antennas.
2. Description of the Related Art
Autonomous and semi-autonomous vehicle functions are increasing in popularity. For example, some vehicle manufacturers are currently designing fully autonomous and semi-autonomous vehicles that can drive themselves from a starting location to a destination location. Some other vehicles include collision avoidance features that may warn a driver and/or control operations of a vehicle when detected data indicates that the vehicle may collide with another object. Algorithms for these autonomous and semi-autonomous vehicle features are based on detection of objects in the vicinity of the vehicle, such as street signs, other vehicles, people, and the like.
Many vehicles incorporate radar systems to detect such objects. Vehicular radar systems transmit a radar signal having a frequency of about 80 gigahertz (GHz) through the air. The radar signal is reflected from a target and the reflected signals or waves are then received by the vehicular radar system. The characteristics of the reflected signals are analyzed by a processor or a controller to determine characteristics of the objects that reflected the signal, such as a size of the object, a distance between the object and the vehicle, or the like.
Conventional vehicular radar systems utilize an array of broadside antennas typically printed on a printed circuit board (PCB). Signals transmitted by these broadside antennas propagate in a direction perpendicular to a plane of the PCB. This layout provides for two-dimensional scanning in the direction perpendicular to the plane of the PCB.
Challenges arise, however, when attempting to stack broadside antennas on top of each other. In particular, difficulties arise when attempting to electrically connect an antenna controller to each broadside antenna of stacked arrays of broadside antennas. In order to electrically connect the antenna controller to each broadside antenna, a relatively large area is required for the antennas and connections. This large required area precludes stacked arrays of broadside antennas from having a compact size that is suitable for consumer vehicle use.
Another challenge with stacking broadside antennas is signal interference. For example, a first broadside antenna may be stacked above a second broadside antenna. Because the second broadside antenna transmits a signal in the direction perpendicular to the plane of the PCB, the signal is directed towards the first broadside antenna. The first broadside antenna interferes with the signal from the second broadside antenna, presenting difficulties when processing the signals.
Thus, there is a need for a structural support system and a method for structurally supporting antennas usable for volumetric scanning by vehicular radar systems.